1. Field of the Invention
The present invention relates generally to an optical storage device, and more particularly to a cartridge holding mechanism for an optical storage device.
2. Description of the Related Art
An optical disk has received attention as a memory medium that becomes a core in the recent rapid development of multimedia, and it is usually accommodated in a cartridge case to be provided as an optical disk cartridge for practical use. The optical disk cartridge is loaded into an optical disk drive to perform reading/writing of data (information) from/to the optical disk by means of an optical pickup (optical head).
A recent optical disk drive intended to realize size reduction is composed of a fixed optical assembly including a laser diode module, a polarization beam splitter for reflecting and transmitting a laser beam, and a photodetector for receiving reflected light from an optical disk, and a movable optical assembly including a carriage and an optical head having an objective lens and a beam raising mirror mounted on the carriage. The carriage is movable in the radial direction of the optical disk along a pair of rails by means of a voice coil motor.
A write-power laser beam emitted from the laser diode module of the fixed optical assembly is first collimated by a collimator lens, next transmitted by the polarization beam splitter, next reflected by the beam raising mirror of the optical head, and finally focused on the optical disk by the objective lens, thereby writing data onto the optical disk. On the other hand, data reading is performed by directing a read-power laser beam onto the optical disk. Reflected light from the optical disk is first collimated by the objective lens, next reflected by the polarization beam splitter, and finally detected by the photodetector, thereby converting the detected optical signal into an electrical signal.
In general, a cartridge holder is used to hold the optical disk cartridge in the optical disk drive. Further, a spring mechanism as an independent component for firmly holding the cartridge is mounted on the cartridge holder, so as to prevent the play (rattling) of the cartridge in the cartridge holder due to vibration or shock. However, the optical disk is a removable medium, and there are slight variations in size of the cartridge, differences in material of the cartridge, and differences in surface finished condition of the cartridge due to differences in cartridge maker. According to these differences and differences in use frequency (the number of insertions and ejections) of the cartridge, there occur variations in frictional force generated between the cartridge surface and the cartridge holder or another sliding member such as a drive base in the optical disk drive. Accordingly, even in the same optical disk drive, the amount of ejection of the cartridge tends to vary because of such variations in frictional force.
To suppress such variations in the amount of ejection of the cartridge, the conventional cartridge holding mechanism is provided with means for minimizing a change in elastic force of the spring mechanism for holding the cartridge, or provided with a hook mechanism or brake mechanism for stopping or braking the cartridge during ejection. However, such a conventional cartridge holding mechanism employing a spring mechanism as an independent component has a problem of cost increase due to an increase in parts count, an increase in man-hour for parts mounting, and an increase in man-hour for parts managing, for example.
It is therefore an object of the present invention to provide a cartridge holding mechanism for an optical storage device which can stably hold a cartridge in the device and can obtain a stable frictional force in ejecting the cartridge out of the device.
In accordance with an aspect of the present invention, there is provided an optical storage device capable of accepting a cartridge comprising a cartridge case and an optical recording medium accommodated in said cartridge case, and reading information recorded on said optical recording medium, comprising a base; a light source mounted on said base; an optical head having an objective lens for focusing light from said light source onto said optical recording medium; a photodetector mounted on said base for detecting a regenerative signal from reflected light from said optical recording medium; a cartridge holder having a main surface for holding said cartridge inserted in said optical storage device; a first cartridge pressure spring mounted to a side portion of said cartridge holder in the vicinity of a first side of said cartridge holder so as to be pivotable about a first pivotal axis substantially parallel to said main surface, said first cartridge pressure spring extending substantially in a longitudinal direction of said cartridge holder corresponding to a direction of insertion of said cartridge into said optical storage device; a second cartridge pressure spring mounted to another side portion of said cartridge holder in the vicinity of a second side of said cartridge holder opposite to said first side so as to be pivotable about a second pivotal axis substantially parallel to said main surface, said second cartridge pressure spring extending substantially in said longitudinal direction of said cartridge holder; a pair of first projections formed at opposite end portions of said first cartridge pressure spring for making pressure contact with said cartridge; and a pair of second projections formed at opposite end portions of said second cartridge pressure spring for making pressure contact with said cartridge.
Preferably, said first cartridge pressure spring has a weight balance such that a front portion of said first cartridge pressure spring corresponding to a front end of said optical storage device from which said cartridge is inserted is lighter in weight than a rear portion of said first cartridge pressure spring with respect to said first pivotal axis; and said second cartridge pressure spring has a weight balance such that a front portion of said second cartridge pressure spring corresponding to said front end of said optical storage device is lighter in weight than a rear portion of said second cartridge pressure spring with respect to said second pivotal axis. The first cartridge pressure spring has a pair of first raised portions having aligned holes, and said second cartridge pressure spring has a pair of second raised portions having aligned holes. The cartridge holder has a pair of third raised portions having aligned holes, and a pair of fourth raised portions having aligned holes.
The optical storage device further comprises a first pin inserted through said aligned holes of said first raised portions and said aligned holes of said third raised portions for pivotably supporting said first cartridge pressure spring to said cartridge holder, and a second pin inserted through said aligned holes of said second raised portions and said aligned holes of said fourth raised portions for pivotably supporting said second cartridge pressure spring to said cartridge holder. The first and second cartridge pressure springs are formed of metal such as stainless steel and phosphor bronze. The first and second cartridge pressure springs may be formed of molded resin. In this case, the first pin is integral with the first cartridge pressure spring, and the second pin is integral with the second cartridge pressure spring.
In accordance with another aspect of the present invention, there is provided a cartridge holding mechanism for a storage device, comprising a base; a cartridge holder having a main surface for holding a recording medium cartridge inserted in said storage device, in cooperation with said base; a first cartridge pressure spring mounted to a side portion of said cartridge holder in the vicinity of a first side of said cartridge holder so as to be pivotable about a first pivotal axis substantially parallel to said main surface, said first cartridge pressure spring extending substantially in a longitudinal direction of said cartridge holder corresponding to a direction of insertion of said cartridge into said storage device; a second cartridge pressure spring mounted to another side portion of said cartridge holder in the vicinity of a second side of said cartridge holder opposite to said first side so as to be pivotable about a second pivotal axis substantially parallel to said main surface, said second cartridge pressure spring extending substantially in said longitudinal direction of said cartridge holder; a pair of first projections formed at opposite end portions of said first cartridge pressure spring for making pressure contact with said cartridge; and a pair of second projections formed at opposite end portions of said second cartridge pressure spring for making pressure contact with said cartridge.
Preferably, said first cartridge pressure spring has a weight balance such that a front portion of said first cartridge pressure spring corresponding to a front end of said storage device from which said cartridge is inserted is lighter in weight than a rear portion of said first cartridge pressure spring with respect to said first pivotal axis; and said second cartridge pressure spring has a weight balance such that a front portion of said second cartridge pressure spring corresponding to said front end of said storage device is lighter in weight than a rear portion of said second cartridge pressure spring with respect to said second pivotal axis.
The above and other objects, features and advantages of the present invention and the manner of realizing them will become more apparent, and the invention itself will best be understood from a study of the following description and appended claims with reference to the attached drawings showing some preferred embodiments of the invention.